Improvement in sewing-machines



mi" raras PATENT OFFICE.

VILLIAM CHICKEN, OF CHELSEA, MASSACHUSETTS.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 72,9711; dated January'7, 1568.

To all whom it may concern:

Be it known that I, WILLIAM CHICKEN, of Chelsea, in the county ofSuffolk and State of lVIassa-chusetts, have invented a new and usefulImprovement in Button-Hole Machines; and I do hereby declare thatthefollowing, taken in connection with the drawings which accompany andform part ot' this specification, is a description of my inventionsucient to enable those skilled in the art to practice it.

This invention is an improvement on the button-hole machine made underthe United States Letters Patent granted for the invention of D. W. G.Humphrey August 29 Aand October 3, 1865, Aand now generally known as theUnion Button-Hole Machine, and it relates specially ,to an improvementiu the means for rotating the disk which operates the cloth clamp orholder, to effect the feed of the work and present properly the edges ofthe cut in the material to the action of the stitch-forming mechanism.In said machines the cloth-clamp is moved by the conjoined actionthereon of a camgroove cut in a 1otat-ing disk intermittently operatingon a pin, which passes through a slot of peculiar form cut through aiiXed plate placed over said rotating disk. This disk in the UnionButton Hole Machines receives its rotation from a pawl acting onratchet-teeth cut in the edge ofthe disk the fault of this being thatthe disk can only be moved in rotation at each intermission an amount orangle which is determined by the act-ion of the pawl on one, two,

' or more teeth, there being no way in which the movement of the diskcan be made through the space represented by any fraction of one of theratchet-teeth.

The object ot' my invention is to remedy the defect mentioned byproviding a means by which the movements of the disk may he madeWhatever is desired, instead ot' being contned to Afixed divisions ot' acircle, like those of ratchet-teeth.

The drawing is a plan of a portion of the underneath surface of the topof the body or bed of a button-hole sewing-machine, from which all theparts not immediately connected with the gist of my invention areremoved.

a represents the part of the body of the machine specified.

b is the rotating disk, which operates to move the cloth-clamp by acam-groove in the Aside opposite to that shown, as in Humphreys,

`of a thickness equal tothev projection of the iian ge from the plate orweb of the pinion.

On the surface of the eccentric is pivoted av lever, e, to the outer orlong arm of which is hinged a curvilinear wedge, f, which tits in theL1une-like recess left between the eccentric and the flange of thepinion. On the same stud or shaft on whichl the pinion c is placed is alever, g, the long arm of which is provided with a pin or friction-roll,It, intended to mesh into a grooved cam, by which motion'is given to theleverg, which efi'ects, through the mechanism described herein, movementofthe disk b.

The lever e has its short arm entered into a mortise made in lever g,the mortise being' slightly larger than the enterin gend of lever e,which, consequently, is allowed a slight play or movement with respectto lever g, though subject to be moved thereby and there is xed to leverg a spring, i, which, by contact with lever c, keeps a definite relationbetween the two levers g and c, except when 'force enough is applied tolever e to deiiect the spring i. v

To the short-arm of lever g is, hinged, by pivot j, an arm, k, which hasa capability of movement at right angles to the plane surface of theeccentric, the spring l having for its function the keeping of arm Lpressed constantly toward the eccentric.

In the wedge j' there is a pin, n, the outer end of which is inclined,so as to let the arm 7c pass over the end of the pin as the arm ispressed away from the surface of the eccentric, as occurs by contact ofthe end ofthe arm with either of the inclined surfaces m and o.

The tendency of the spring 'i is to force thewedgef between the rim ofpinion c and the eccentric d, and thus cause a frictional union betweenthe pinion and the eccentric, that shall cause them to move together asone piece; but when the piece k is not lifted by one or the other of theinclines m or oit acts as a bar against pin n in the wedge f, and keepsthe spring -from forcing the wedge tightly between the pinion-rim andthe eccentric.

When the long arm of the lever g is started and moved by any suitablecam in the direction indicated by the arrow z, the arm k takes and keepsa position in 'which the pin u abuts against the side of the arm, sothat the wedge cannot move with reference to said arm, and no union orbinding ot` the pinion to the eccentric can take place while the longarm of g nieves in direction of arrow z.

When the cam which acts upon the long arm of the lever returns it in thedirection indicated by the arrow y no turning of the pinion is effectedtill the arm 7c strikes one or the other of the inclines o or m and islifted, so that spring t' can push the arm c toward arm k, and thuscauses the wedge to bind together the eccentric and the pinion, so thatfurther movement of the long arm of g in the direction of arrow y willbe utilized-in partially rotating the geared cam-disk b, which operateson the cloth-clam p.

In feeding around the eye of a button-hole it is necessary to have thefeed-movement considerably greater in extent than the feed-movementalong the straight sides of the hole, and to effect this change intheextent of the feedmovement automatically there is cut in the diskanother cam-groove than the one before referred to, the function ofwhich is to operate a lever7 p, so as at the proper times to throw theincline o into and ont of the path ot' the the vibration of arm It'.

The cam-groove which operates arm 19 is /l marked q, and when itoperates to move the arm p and incline o into the position shown in` redlilies, then the arm It' is lifted sooner than it is when arm 19 is inthe other position shown,

and the extent of feed given is that suited for The detail marked A is across-section taken through the disk b anda portion of the top of thebed, showing the stationary plate in which the cam-groove is cut, theplate being marked r, and the cam-groove therein s, while the cam-groovein the disk, which, in connection with cam-groove s, operates on theclothclamp, is marked t.

rlhe pinion marked u is to be rotated by a wrench by the operator, andis used onlyr for the purpose of moving the disk b independently of theregular feed mechanism, to bring back the disk to proper position forworking a new button-hole after one has been previously completed.

In combination with a disk provided with gear-teeth and having a'cam forworking in connection with a stationary plate-cam, as described, apinion which meshes into the teeth of the disk, and on which pinion africtionclamp or gripe operates to impart intermit-v tent rotativemovements to said disk, for the purpose of giving movement to a stock orcloth-clamp, substantially as described.

WILLIAM oHIoKEv.

Vitnesses J1 B. CROSBY, FRANCIS GOULD.

